Tail Rotor Problems
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I mentioned this on a different topic, but Rotorque mentioned throttle control in autorotation on the previous page and so I thought I'd mention it again. In singles with throttle on the collective, reducing pitch but leaving the throttle alone and Nr in the normal range may produce just the right amount of torque to balance the transmission bearing drag at normal auto airspeed. However, during the collective application at the end, throttle will have to be held at idle to prevent the correlator from sending the power back up, and in the case of TR failures, this will leave a healthy yaw to contend with as the transmission bearing drag becomes unopposed. I suppose that a near zero speed landing would be something to consider in this case, if possible.
Guest
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I've had a tail rotor control jam on me, the wires jumped the control run guide pulleys and the pitch setting luckily was jammed to a +ive setting. Luckily we were shore side at the time otherwise I would have had to recover to 3000 tons of moving deck the size of a car parking slot!!!
One of two things will happen to you if it is going to happen:
1. There will be an almighty bang accompanied with the inherent yaw in oppostion to the direction of the main rotors. If you are in fwd cruise then the rate will be in proportion to your speed. [In the hover, you will rotate very very quickly, so much so that you will become very disorientated and if not strapped in properly, will be flung outboard of the rotation. Should this be away from the throttle(s) then you won't be able to chop it/them]. The simple solution here is dump the lever and land, accept the very hard landing!!
In fwd flight you will also get a fwd pitch of the a/c dependant on the moment arm of the TR x weight (of chunk)lost! If a/c is still flyable: YOU MUST ENTER AUTO AND CHOP THOSE THROTTLES ASAP. At the bottom, the flare will assist with yaw correction but not fully, you will be committed to a zero spd landing if you don't want to flip head over heels. Keep the Nr up at max throughout, this too helps with yaw correction.
2. You will experience an undemanded yaw input proportional to collective input and possibly slight mechanical noises. This baby should give you time to change your underwear and hand over to the commander!!!
This scenario has been superbly described by others earlier. Time is on your side.
Concrete is better for landing because the skids/undercarriage can scrape more easily over concrete. Don't land on grass if possible. Do as many approaches as necessary before the real Mcoy, as long as you don't go below min pwr speed on each approach you won't lose heading control...Get rid of fuel,if possible. If you can limp to a major airport, get them to foam a strip of runway.
Go thru what you would do, every month or so, get a feel for your craft, play with stuck pedal/speed/collective/wind...this is what makes a professional stand out from a joy rider. Last but not least: DO A GOOD WALKROUND EVERY TIME.
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Thermal runaway.
[This message has been edited by Thomas coupling (edited 14 February 2001).]
One of two things will happen to you if it is going to happen:
1. There will be an almighty bang accompanied with the inherent yaw in oppostion to the direction of the main rotors. If you are in fwd cruise then the rate will be in proportion to your speed. [In the hover, you will rotate very very quickly, so much so that you will become very disorientated and if not strapped in properly, will be flung outboard of the rotation. Should this be away from the throttle(s) then you won't be able to chop it/them]. The simple solution here is dump the lever and land, accept the very hard landing!!
In fwd flight you will also get a fwd pitch of the a/c dependant on the moment arm of the TR x weight (of chunk)lost! If a/c is still flyable: YOU MUST ENTER AUTO AND CHOP THOSE THROTTLES ASAP. At the bottom, the flare will assist with yaw correction but not fully, you will be committed to a zero spd landing if you don't want to flip head over heels. Keep the Nr up at max throughout, this too helps with yaw correction.
2. You will experience an undemanded yaw input proportional to collective input and possibly slight mechanical noises. This baby should give you time to change your underwear and hand over to the commander!!!
This scenario has been superbly described by others earlier. Time is on your side.
Concrete is better for landing because the skids/undercarriage can scrape more easily over concrete. Don't land on grass if possible. Do as many approaches as necessary before the real Mcoy, as long as you don't go below min pwr speed on each approach you won't lose heading control...Get rid of fuel,if possible. If you can limp to a major airport, get them to foam a strip of runway.
Go thru what you would do, every month or so, get a feel for your craft, play with stuck pedal/speed/collective/wind...this is what makes a professional stand out from a joy rider. Last but not least: DO A GOOD WALKROUND EVERY TIME.
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Thermal runaway.
[This message has been edited by Thomas coupling (edited 14 February 2001).]
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Chaps,
Loads of very interesting, well formulated hypothesis and real experiences alike. For my ha'peth worth there is no substitute for simulation. Most see the merits of a half decent sim for practicing those failures that we dare not try in reality (bearing in mind for the bean-counters present; we wreck more aircraft in training than in Operations!). This was certainly true of my experience with FSI's 212 sim at Fort Worth. Among the many any other failures, we underwent simulated T/R drive-shaft failures. The Company policy was 'find big space - enter auto - live happily ever after! The FSI instructors however had a different idea - they advocated and trained the 'find some sort of flight attitude with forward speed, run on to runway with power, gently rolling off throttle and lowering collective, to a gentle if graunching stop.' First try, I managed several pirouettes culminating in a nice little roll (no 10/10 from the judges there then!). After a couple of attempts I could get down in one piece but it still frightened me to death. My conclusion was that if confronted with the reality, I would tow the Company line - I truly felt that I would have a far better chance of walking away as autos are far more regularly practiced. I would would maybe reconsider if sim training was the 'norm' and I got to practice the FSI way on a yearly basis.
Loads of very interesting, well formulated hypothesis and real experiences alike. For my ha'peth worth there is no substitute for simulation. Most see the merits of a half decent sim for practicing those failures that we dare not try in reality (bearing in mind for the bean-counters present; we wreck more aircraft in training than in Operations!). This was certainly true of my experience with FSI's 212 sim at Fort Worth. Among the many any other failures, we underwent simulated T/R drive-shaft failures. The Company policy was 'find big space - enter auto - live happily ever after! The FSI instructors however had a different idea - they advocated and trained the 'find some sort of flight attitude with forward speed, run on to runway with power, gently rolling off throttle and lowering collective, to a gentle if graunching stop.' First try, I managed several pirouettes culminating in a nice little roll (no 10/10 from the judges there then!). After a couple of attempts I could get down in one piece but it still frightened me to death. My conclusion was that if confronted with the reality, I would tow the Company line - I truly felt that I would have a far better chance of walking away as autos are far more regularly practiced. I would would maybe reconsider if sim training was the 'norm' and I got to practice the FSI way on a yearly basis.
Guest
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To all who responded to my request for a discussion on TR failure, a great thanks. Lots of food for thought here. Thanks particularly to Eden for his book on the subject. I am more sure than ever that at 75 hrs of heli time, I do NOT want to face a TR problem. But, like autos, I will try to practice it regularly. The repetition won't necessarily help, but, at least, there will likely be less of a feeling of panic if it occurs. Keep the thread going, please!
Guest
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Little finger rule-
When your left hand is curled around the throttle stretch out your little fimger (LH!)
As you decrease throttle (the nose would yaw
more left) your finger will point left. Apply the reverse to increasing throttle.
The nose will yaw right as your finger points right.
Good for trimming up for a run- on from jammed controls (depending on the nature of the problem).
When your left hand is curled around the throttle stretch out your little fimger (LH!)
As you decrease throttle (the nose would yaw
more left) your finger will point left. Apply the reverse to increasing throttle.
The nose will yaw right as your finger points right.
Good for trimming up for a run- on from jammed controls (depending on the nature of the problem).
Guest
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To Eden
Sorry if my response to you sounded as if I was telling you it wasn't intended that way at all. Its just that most of my flying has been on the NOTAR system, and most people have never had the chance.(I'll send you an email)As said before its very similar to a tail rotor but with some particular differences (some good some bad). Again sorry if my response sonded like I was setting you straight "I'm here to learn not preach"
Reagrds
hoverbover
Sorry if my response to you sounded as if I was telling you it wasn't intended that way at all. Its just that most of my flying has been on the NOTAR system, and most people have never had the chance.(I'll send you an email)As said before its very similar to a tail rotor but with some particular differences (some good some bad). Again sorry if my response sonded like I was setting you straight "I'm here to learn not preach"
Reagrds
hoverbover
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I have posted this on several other threads and on another forum. Although there was no actual tailrotor failure the pilot perceived that the tailrotor gearbox had suffered a failure and as a result took corrective action which only made things worse. This could also be posted on the wire strike thread.
I was flight mechanic on a Bell HTL-1 (early model 47) and we were returning to base in Traverse City, Michigan from a stint on an Ice Breaker on Lake Superior. We had a leaky tail rotor gearbox so every fifty miles or so we would land and I would fill up the gearbox with of all things, fish oil. Very smelly stuff. My pilot, Dave Gershowitz, who incidentally was the first helicopter pilot to hit 1000 hours, was easily freaked out.
While flying in the left seat I was holding the oil can between my legs and reading a map. We were about twenty minutes out when Dave saw a bear. He very excitedly told me to look. When I leaned over, my legs spread and the can hit the deck making a loud noise. Dave thought there was something wrong with the tail rotor gearbox and he made a quick turn looking for a spot to land. In the process of making his maneuver he really made a hard over. On that particular helicopter type when there was an excessive side load on the mast it would cause the planetary gears to really growl.
Upon hearing that, he really wanted to get on the ground. He picked out a landing spot in front of what we later found out was a veterinarians office. To get from where we were to that landing spot we had to pass over a turkey farm and in the process we made the turkeys stampede and over 100 birds were killed in the pileup at the fence surrounding the turkey farm.
Oh yes, in the process of landing, we took out the vets' telephone line
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The Cat
I was flight mechanic on a Bell HTL-1 (early model 47) and we were returning to base in Traverse City, Michigan from a stint on an Ice Breaker on Lake Superior. We had a leaky tail rotor gearbox so every fifty miles or so we would land and I would fill up the gearbox with of all things, fish oil. Very smelly stuff. My pilot, Dave Gershowitz, who incidentally was the first helicopter pilot to hit 1000 hours, was easily freaked out.
While flying in the left seat I was holding the oil can between my legs and reading a map. We were about twenty minutes out when Dave saw a bear. He very excitedly told me to look. When I leaned over, my legs spread and the can hit the deck making a loud noise. Dave thought there was something wrong with the tail rotor gearbox and he made a quick turn looking for a spot to land. In the process of making his maneuver he really made a hard over. On that particular helicopter type when there was an excessive side load on the mast it would cause the planetary gears to really growl.
Upon hearing that, he really wanted to get on the ground. He picked out a landing spot in front of what we later found out was a veterinarians office. To get from where we were to that landing spot we had to pass over a turkey farm and in the process we made the turkeys stampede and over 100 birds were killed in the pileup at the fence surrounding the turkey farm.
Oh yes, in the process of landing, we took out the vets' telephone line
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The Cat
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Hoverbover: no bad feeling taken - I was being very genuine about my ignorance and I am grateful for your info' - I look forward to your email and hope you can provide me with some more detail as to how the thing works.
I am going to have a look at a Notar machine in the next week or so and would appreciate as much background info on tail rotor snags that you can provide about it.
I too am here to learn and I hope never to preach too hard - cheers
eden - energy driven eccentric nirvana
I am going to have a look at a Notar machine in the next week or so and would appreciate as much background info on tail rotor snags that you can provide about it.
I too am here to learn and I hope never to preach too hard - cheers
eden - energy driven eccentric nirvana
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NOTAR itself really has moved the tail "rotor" into the body of the machine itself. A fan unit run off the trannie sends high pressure air into the boom, the air is then forced out thru two slots on the side, and due to coranda effect helps to offset torque, the rest of the air is coming out of the variable nozzle at the aft end, in which the amount can be adjusted by the pilot.
The vertical vins are also controlled by the bilot and the SAS.
A basic description. But as hoverbover was saying, since the fan is now inside the fuse you could sit all day with the boom in a tree (McD loves pics of this) with no problems
Yopu are less likely to have things hit the fan too.
Boy what a great thread! Lot's of stuff to absorb. My hope is that if I suffer a tail issue, it's a control one with time to sort it out, if not them I'm into auto and hope for the best.
SPS: Like your 'lil pinkie trick!
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Marc
The vertical vins are also controlled by the bilot and the SAS.
A basic description. But as hoverbover was saying, since the fan is now inside the fuse you could sit all day with the boom in a tree (McD loves pics of this) with no problems
Yopu are less likely to have things hit the fan too.Boy what a great thread! Lot's of stuff to absorb. My hope is that if I suffer a tail issue, it's a control one with time to sort it out, if not them I'm into auto and hope for the best.
SPS: Like your 'lil pinkie trick!
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Marc
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To Eden
Hope you got the email, so that everyone can understand(hopefully I might even understand it myself one day)I am posting my thoughts about the NOTAR here(I dont wish to divert the thread,but I dont think it warrants its own one and is kind of related)
The NOTAR system basically works from air pressure created by a fan at the front of the Tail Boom (Tube)This fan is driven by the turbine in the same way as any TR drive.
The fan is very similar to A FENESTRON in looks but with very short blades (about 60mm in length)The fans pitch is increased and decreased/coupled to the pedal inputs(Strangely enough it increases pitch in both directions) and consequently greater pedal input creates greater pressure in the tube.
at the end of the Tail Boom there is (for want of abetter expression) a rotating dustbin which allows the air pressure in the tube (from memory its around 3psi)to be directed for pedal turns in the hover.
There are also two long slots on one side of the boom (and a diffuser on the otherside)which are configured so that air continually comes out of the slots in a downward direction,so that in the hover the downwash from the Main Rotor Flows over the boom and using the principal of there then being a low pressure one side and highpressure the otherside of the boom (Coanda effect I think)This also creates some of the anti torque in the hover (think its 20 %)
Obviously as you move into forward flight the downwash is not flowing over the boom and the air pressure from the bucket is less effective so the 2 Rear verticals are also connected to the pedals (either by cable or in some configurations by linear motor)so in forward flight you have rudders!
And there you have it simple,a bit like me.
Flying it is very similar to a normal TR but the following are what I find to be the differences.
1.Firstly in the hover the pedals need a lot of movement,but in forward flight they are VERY sensitive (unless AC is YSAS equipped)
2.When its windy the pedal movements are quite big in the hover,but still plenty of power.
3.As the tail goes thru the wind there is no snap like a TR, everything seems far smoother
4.When you are coming into the hover from forward flight you actully have to apply more right pedal (as the downwash sticks to the boom)before a big boot of left.
5.In flight the vibrations/resonance of a tailrotor is non existant so its very smooth
With these in mind its just like any helicopter it has quirks,but I guess you learn to live with them and being a low hour pilot and having spent 50/50 in TRs and Notars I havent built up any great aversion to them. But when you land in a forest or in fact anywhere (even an airfield) not having to worry about people walking into(airfields) or things hitting the tail rotor does allow some comfort(I know the LZ is always checked and scrutinized but this thread would be here if accidents didnt sometimes happen,and its amazing how a running TR looks like a bicycle wheel to our canine friends who shouldnt be off alead but sometimes appear from nowhere.)
Autos:
These feel very similar to a normal TR.
TR Failures:
Again very similar but if the fan fails in forward flight you can actually land (at 40 knots ) using the rudders, having tried this to the concrete and to the grass it is a wild ride! (ever tried slowing down on skids on concrete with no TR authority form 40 Knots?and yes using the throttle/finger pointing method helps but you have to be quick to make it stay on the runway and not go pirouetting onto the grass)
As said before stuck pedals can be alot worse than normal TR because of the effect of the rear verticals
Problems:
Havent really found any yet, some people say that in heavy rain the fan has problems but having flown in heavy(maybe not american heavy)rain I have not found any problems.
Just make sure no one has thrown a bag of bolts in the fan intake on the walk round (can you believe this has actually happened to one, and it still flew,not as quietly though and there were a few red faces)
This is how I understand it,and have tried to make it as understandable as possible with goinginto the real tech side of it (that would tax my brain too much)and Im sure other NOTAR pilots will hopefully have more to add,with differing opinions I should think
Unfortunately some LOVE it some HATE it,me I just enjoy flying it.
Regards
hoverbover
Hope you got the email, so that everyone can understand(hopefully I might even understand it myself one day)I am posting my thoughts about the NOTAR here(I dont wish to divert the thread,but I dont think it warrants its own one and is kind of related)
The NOTAR system basically works from air pressure created by a fan at the front of the Tail Boom (Tube)This fan is driven by the turbine in the same way as any TR drive.
The fan is very similar to A FENESTRON in looks but with very short blades (about 60mm in length)The fans pitch is increased and decreased/coupled to the pedal inputs(Strangely enough it increases pitch in both directions) and consequently greater pedal input creates greater pressure in the tube.
at the end of the Tail Boom there is (for want of abetter expression) a rotating dustbin which allows the air pressure in the tube (from memory its around 3psi)to be directed for pedal turns in the hover.
There are also two long slots on one side of the boom (and a diffuser on the otherside)which are configured so that air continually comes out of the slots in a downward direction,so that in the hover the downwash from the Main Rotor Flows over the boom and using the principal of there then being a low pressure one side and highpressure the otherside of the boom (Coanda effect I think)This also creates some of the anti torque in the hover (think its 20 %)
Obviously as you move into forward flight the downwash is not flowing over the boom and the air pressure from the bucket is less effective so the 2 Rear verticals are also connected to the pedals (either by cable or in some configurations by linear motor)so in forward flight you have rudders!
And there you have it simple,a bit like me.
Flying it is very similar to a normal TR but the following are what I find to be the differences.
1.Firstly in the hover the pedals need a lot of movement,but in forward flight they are VERY sensitive (unless AC is YSAS equipped)
2.When its windy the pedal movements are quite big in the hover,but still plenty of power.
3.As the tail goes thru the wind there is no snap like a TR, everything seems far smoother
4.When you are coming into the hover from forward flight you actully have to apply more right pedal (as the downwash sticks to the boom)before a big boot of left.
5.In flight the vibrations/resonance of a tailrotor is non existant so its very smooth
With these in mind its just like any helicopter it has quirks,but I guess you learn to live with them and being a low hour pilot and having spent 50/50 in TRs and Notars I havent built up any great aversion to them. But when you land in a forest or in fact anywhere (even an airfield) not having to worry about people walking into(airfields) or things hitting the tail rotor does allow some comfort(I know the LZ is always checked and scrutinized but this thread would be here if accidents didnt sometimes happen,and its amazing how a running TR looks like a bicycle wheel to our canine friends who shouldnt be off alead but sometimes appear from nowhere.)
Autos:
These feel very similar to a normal TR.
TR Failures:
Again very similar but if the fan fails in forward flight you can actually land (at 40 knots ) using the rudders, having tried this to the concrete and to the grass it is a wild ride! (ever tried slowing down on skids on concrete with no TR authority form 40 Knots?and yes using the throttle/finger pointing method helps but you have to be quick to make it stay on the runway and not go pirouetting onto the grass)
As said before stuck pedals can be alot worse than normal TR because of the effect of the rear verticals
Problems:
Havent really found any yet, some people say that in heavy rain the fan has problems but having flown in heavy(maybe not american heavy)rain I have not found any problems.
Just make sure no one has thrown a bag of bolts in the fan intake on the walk round (can you believe this has actually happened to one, and it still flew,not as quietly though and there were a few red faces)
This is how I understand it,and have tried to make it as understandable as possible with goinginto the real tech side of it (that would tax my brain too much)and Im sure other NOTAR pilots will hopefully have more to add,with differing opinions I should think
Unfortunately some LOVE it some HATE it,me I just enjoy flying it.
Regards
hoverbover
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To R W1
You posted while I was typing mine to EDEN sorry mine took so long to say what yours did.
However great the pictures with the NOTAR tail in the tree may look great, ask the guy who stuck his tail into a bush changed pedal input/rotated dustbin caught branches in hole that closed due to bin roating to let air out other side.
Result:cat caught by tail syndrome,and change of underwear for pilot.
Luckily he got away with it but the notar isn't infallable.!!!!!!!!!!!
Regards
hoverbover
You posted while I was typing mine to EDEN sorry mine took so long to say what yours did.
However great the pictures with the NOTAR tail in the tree may look great, ask the guy who stuck his tail into a bush changed pedal input/rotated dustbin caught branches in hole that closed due to bin roating to let air out other side.
Result:cat caught by tail syndrome,and change of underwear for pilot.
Luckily he got away with it but the notar isn't infallable.!!!!!!!!!!!
Regards
hoverbover
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Hover,
Heard about that one myself .....
Nothing perfect hehe ....
Liked your description, I had left out the variable aspect of the fan for simplicity, but you are right. Mine was a Q&D response.
The slots and high pres air add energy to the boundry layer of the airflow going around that side of the boom delaying separation, thus as I understand it intensifying the coanda effect.
I think you meant Florida heavy rain hehehe ...
Now if they could make it so that the heli doesn't look like it has a hige cigar stuck into it's A$$ .......
[This message has been edited by RW-1 (edited 15 February 2001).]
Heard about that one myself .....
Nothing perfect hehe ....
Liked your description, I had left out the variable aspect of the fan for simplicity, but you are right. Mine was a Q&D response.
The slots and high pres air add energy to the boundry layer of the airflow going around that side of the boom delaying separation, thus as I understand it intensifying the coanda effect.
I think you meant Florida heavy rain hehehe ...
Now if they could make it so that the heli doesn't look like it has a hige cigar stuck into it's A$$ .......
[This message has been edited by RW-1 (edited 15 February 2001).]
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To Imlanphere
The drive to the fan is coupled to the main transmission in the same way as any TR drive,so providing ONLY engine failure and you enter auto its driven in just the same way as normal.
You do actually require the fan to work because after all it is just like losing an normal TR.(NOT GOOD)
Hope this clears it up.
Any other questions on the NOTAR fire away
and I'll try and answer them.
Regards
hoverbover
The drive to the fan is coupled to the main transmission in the same way as any TR drive,so providing ONLY engine failure and you enter auto its driven in just the same way as normal.
You do actually require the fan to work because after all it is just like losing an normal TR.(NOT GOOD)
Hope this clears it up.
Any other questions on the NOTAR fire away
and I'll try and answer them.
Regards
hoverbover
Guest
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Nr fairy -
Hadn't even considered it to be abs. frank, don't fly them often. Good point and we'll leave it to the forum to see what they think (code for I don't know and I have to dash right now!)
RW -
Glad you like the little finger rule - It is just amazing what you can do with one!
Hadn't even considered it to be abs. frank, don't fly them often. Good point and we'll leave it to the forum to see what they think (code for I don't know and I have to dash right now!)
RW -
Glad you like the little finger rule - It is just amazing what you can do with one!
Guest
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Rotorque -
Your thoughts on the tail rotor and the possibility of it entering autorotation are very interesting. I was similarly intrigued when making a study of the TR and I concluded with this –
<i>(Basic facts are established for the benefit of sideline readers and not to patronize anyone)</i>
‘Autorotation’ is a term used for MR harnessing of an incoming airflow to maintian RPM in much the same way as a windmill sails would (except that a windmill is static and the incoming airflow moves to it as wind but the Helicopter moves to the incoming airflow).
In this autorotative state the MR is not driven (rotated) by any power applied through its driveshaft from an engine but by the effect of the airflow, i.e. it is driven in reverse, driving the gearbox and anything connected to it.
The TR never enters autorotation in forward flight as it continues to be driven by the MR through the gearbox. It always receives shaft power for rotation. Whether that power is developed and delivered by an engine or autorotative force from the MR makes no difference at all. The TR is always driven by shaft power transmitted from a power source.
If this is taken one step further it is apparent that the TR is always making some thrust in one direction or another (unless TR blade angles of attack are truly zero or RPM are insufficient, etc.).
A Helicopter (of conventional design) in autorotation experiences ‘friction effect’ on the fuselage which tends to twist it in the opposite direction to torque, i.e. yaw to the left. This means that the TR must be capable of making thrust to either the left or right of the tail. It must balance torque during powered flight (by producing thrust to the right) and friction effect during autorotation (by producing thrust to the left).
So it’s a busy little thing eh?!
SPS
Your thoughts on the tail rotor and the possibility of it entering autorotation are very interesting. I was similarly intrigued when making a study of the TR and I concluded with this –
<i>(Basic facts are established for the benefit of sideline readers and not to patronize anyone)</i>
‘Autorotation’ is a term used for MR harnessing of an incoming airflow to maintian RPM in much the same way as a windmill sails would (except that a windmill is static and the incoming airflow moves to it as wind but the Helicopter moves to the incoming airflow).
In this autorotative state the MR is not driven (rotated) by any power applied through its driveshaft from an engine but by the effect of the airflow, i.e. it is driven in reverse, driving the gearbox and anything connected to it.
The TR never enters autorotation in forward flight as it continues to be driven by the MR through the gearbox. It always receives shaft power for rotation. Whether that power is developed and delivered by an engine or autorotative force from the MR makes no difference at all. The TR is always driven by shaft power transmitted from a power source.
If this is taken one step further it is apparent that the TR is always making some thrust in one direction or another (unless TR blade angles of attack are truly zero or RPM are insufficient, etc.).
A Helicopter (of conventional design) in autorotation experiences ‘friction effect’ on the fuselage which tends to twist it in the opposite direction to torque, i.e. yaw to the left. This means that the TR must be capable of making thrust to either the left or right of the tail. It must balance torque during powered flight (by producing thrust to the right) and friction effect during autorotation (by producing thrust to the left).
So it’s a busy little thing eh?!
SPS
Guest
Posts: n/a
Just caught up on three pages of this thread after a week away, and off for another week in a couple of hours so will have to leave it for now. But one thing now really really bothers me. In company with someone else a page or so back, I never practised anything concerning tail rotor failure for my PPL, or while practising emergency procedures with an instructor sometime afterwards. I once mentioned stuck pedals to an instructor at some point, and got a quick little demo, but that was all. The fact that I'd read about what to do seemed to keep everyone happy. Doesn't keep me happy, now I think about it. Think I might find another instructor, or another school, and learn about this.
What are other PPLs' experiences on this? And many thanks to all who've contributed to this most interesting thread.
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Whirly
To fly is human, to hover, divine.
What are other PPLs' experiences on this? And many thanks to all who've contributed to this most interesting thread.
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Whirly
To fly is human, to hover, divine.
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Posts: n/a
Sorry, been away - excellent thread.
Going back to a comment on page 1 by ShyT concerning throttle position in turbine helis, I'm pleased to say that the layout in the Bell 205 (throttle on the collective) saved an oppo of mine in Oman in 1983. He was in the hover over an underslung load at Saiq (6,300 ft amsl, OAT 20 deg...) when the tail rotor decided it didn't want to play any more. He rolled the throttle shut, kept the aircraft level and cushioned the touchdown with no damage to aircraft, aircrew, ground hook-up party or even the load. Top stuff - proves that what's been written in this forum really works.
Going back to a comment on page 1 by ShyT concerning throttle position in turbine helis, I'm pleased to say that the layout in the Bell 205 (throttle on the collective) saved an oppo of mine in Oman in 1983. He was in the hover over an underslung load at Saiq (6,300 ft amsl, OAT 20 deg...) when the tail rotor decided it didn't want to play any more. He rolled the throttle shut, kept the aircraft level and cushioned the touchdown with no damage to aircraft, aircrew, ground hook-up party or even the load. Top stuff - proves that what's been written in this forum really works.